Hydraulic operating mechanism



Oct. 20, 1931. E. CANNON I 1,828,643

HYDRAULIC OPERATING MECHANISM Filed March 26, 1926 s Sheets-Sheet 1 l rl I I Oct. 20, 1931. E. CANNON 1,828,643

HYDRAULIC OPERATING MECHANISM Filed March 1926 3 Sheets-Sheet 2 E4CANNON HYDRAULIC OPERATING MECHANISM Oct. 20, 1931.

Filed March 26 1925 Al fifi l gs lylllllllllllls g/ A Illllllllll 3Sheets-Sheet 3 Patented Oct. 21), 1931 UNITED, STATES] PATENT OFFICE-EARL CANNON, OF PHILADELPHIA, rmmsnvanmaass mnoa TO AMERICAN FLUIDMOTORS COMPANY, 01 PHILADELPHIA, PENNSYLVANIA, A CO IPORA TION OF' PENN-SYLVANIA masons ormrxne-mcnmsu" Applleatlon filed larch 2 8, 1926.Serial No. 97,797.

My invention relates to fluid-power apparatus, and it has for one objectthe pr6v1s1on of fluid-operating mechanism for ash gates and the like.

Another object of myinvention is to provide a fluid power system,wherein a doubleacting cylinder may be controlled by a threeway valve.

A further object of my invention is to provide a power s stem of thecharacter described that shal include a fluid motor having equal pistonspeeds in op site directions.

A still further object o my invention is to provide means, whereby thekinetic energy of the moving piston may be translated into heat energywhen the piston is to be brought to rest,the heat energy being carriedaway by the discharging motive fluid and the various parts therebymaintained at suitable operating temperatures.

With these and other objects and applications in mind, my inventionfurther consists in the details of construction and operationhereinafter described and claimed and illustrated in the accompanyingdrawings, wherein Fig. 1 is a side elevational view, partially insection, of one embodiment of my inven-' tion;

Fig. 2 is an enlarged detail view, partially in section, of the fluidmotor and connected parts, the piston being in its extreme innerposition and the three-way valve positioned to cause the piston to moveto the right; and

Fi .3 is a similar view but illustrating the position of the three-wayvalve when the piston is to be moved to the left.

Referring to the drawings a fluid motor 1 comprises an elongated cyhnder2 having a piston 3 provided with a rod 4 which extends through astufling box 5 in an outer end 6 of said cylinder. The rod 4 iscorinected to an ash gate 7 which is operative to control an outletopening 8 of ash-discharging apparatus 9. This application of myinvention is given principally for the purpose of showing how varied maybe the various forms thereof without departing from the fundamentalfeatures of my invention.

- The cylinder 2 is provided at an inner end three-way va 11 with a mainadmission port 12 and at the outer end 6 with a main admission port 13.Fluid may be supplied to the main ports 12 and 13 by a pump 14 having adischarge port 15 connected to a pipe 16 provided with branches 17 and18 which are respectively connected to the main ports 12 and 13. 7 Thuspropelling fluid may be supplied to both sides of the piston 2 and, byreason of the diiferential pressure areas resulting from the presence ofthe piston rod 4, the piston 3 moves from the closed end 11 of thecylinder 2 to the outer end 6 thereof, all as will presently appear. Thepump 14;, which may take the form of the Hele-Shaw and Martineau pumpdescribed in Patent No. 1,077,979, dated Nov. 11, 1913, has a suctionport 19 connected by a pipe 21 to a storage chamber 22 formed in the edlate 23.

y invention contemplates the operation of the double-acting fluid motor2 by means of a three-way valve'24 having ports 25, 26 and 27. The valve24 also has a movable element 28, whereby the port 26 may be connectedto the port 25 or to the port 27 depending upon the position of anoperating handle 29. The with the branch 17 that the former is directlyconnected to the pump discharge ort 15. and the latter to the main port12. he port 27 may be connected to an exhaust pipe 31 WhlGh leads to thestorage chamber 22.

When the valve element 28 is in the position shown in Fi 2 and thepiston 3 is in the dot-and-dash ine position, the port 12 as well, asthe port 13 are directly connected to the pump dlscharge port 15, withthe result that the piston 2 is actuated toward the outer cylinder end 6at a speed proportional to the difi'erence in pressure areas on theopposite sides of the piston 3. However, when the in Fi 3 and the piston3 occupies the dotandash line posltion, the port 13 only is connected tothe pump discharge port 15 smce the port 12 is now connected to theexhaust pipe 31. As a result, the piston 3 is moved toward the closedend 11 of the cylinder 2. The resulting discharge from the closed end 11is carried by the exhaust pipe 31 to'the ve 24 is in the-position shown1 ports 25 and 26 are so associated storage chamber 22 and subsequentlyconveyed through the pipe 21 to the suction port 19 of the pump 14.

It is desirable in certain classes of work, for example, thatillustrated in the drawings, that the speed of the piston 3 shall beequal for both forward and return strokes for equal pump discharges. Tothis end, I so design the parts of the fluid motor '1 that the arearepresented by the difference between the cross-sectional area of thepiston 3 and the piston rod 4 is equal to the cross-sectional area ofthe piston rod 4. The reason for such proportions is apparent in view ofFigs. 2 and 3, since for one position of the three-way valve 24, fluidis delivered to both sides of the piston 3 while for another position,fluid is delivered to one side only, the other side being connected tothe exhaust pipe 31.

The main admission ports'12 and 13 are so positioned in the path oftravel of the piston 3 as to be closed by said piston as it moves intoits extreme positions. These positions are illustrated in Figs. 2 and 3.In order to cause the movement of the piston 3 from these extremepositions, I provide auxiliary ports 32 and 33 which are respectivelyconnected through pipes 34 and 35 to the branch pipes: 17 and 18. Thepipe 34 is connected to the portion of the branch 17 intermediate theport 26 of the three-way valve 24 and the main admission port 12. Checkvalves 36 and 37 are respectively included in the pipes 34 and 35,whereby fluid may pass. through said pipes to the ports 32 and 33,whenthe main admission ports 12 and 13 are closed by the piston 3.

A further feature of my invention is the translation of the kineticenergy of the moving piston 3 and associated parts into heat energy whenthe piston 3 approaches the end of its stroke, whereby sa1d piston maybe quickly and easily brought to rest with a minimum of vibration. Thisdesired result is accomplished by connecting relief. valves 38 inpipes39 whlch respectively extend from the auxiliary port side of the checkvalves 36 and 37 to the exhaust pipe 31. Each reliefvalve is set tooperate at such pressure that the volume of oil discharged therethroughunder pressure contains the same amount of energy as in thepiston 3 andassociated moving parts. Thus, each relief valve presents a variableorifice having a maximum opening when the pressure is greatest anddecreasing correspondingly with the pressure.

In operation, assuming the three-way valve 24 in the position shown inFig. 2, fluid is delivered to the inner end 11 of the cylinder 2 throughthe branch pipe 17, the three-way valve 24, the check valve 36, the pipe37 and the auxiliary port 32. Fluid is also delivered to the outer end 6of the cylinder 2 through the branch pipe 18 and the main admission port13. As a result, the piston 2 is moved to the right. When the inner mainadmission port 12 is uncovered, fluid is supplied to the cylinder end 11through this port rather than the auxiliary port 32. The movement of thepiston 3 continues until the outer main admission port 13 is closed,whereupon the piston 3 and associated parts are brought to rest by thedischarge of the fluid from the outer end 6 of the cylinder 2 throughthe relief valve 38.. This method of absorbing the shock incident tosuddenly stopping the piston 3 is particularly advantageous in fluidsystems employing oil rather than air, inasmuch as oil is substantiallyincompressible and would cause the development of excessive pressuresshould the usual compression methods of .stopping the piston 3 beemployed. The

kinetic energy of the moving piston 3 is thus translated into heatenergy in the relief valve which is carried off by the fluid to thestorage chamber 22.

When the piston 3 is to be moved to the inner end 11 of the cylinder 2,the operating lever 29 of the three-way valve 24 is moved from theposition shown in Fig. 2 to that shown in Fig. 3, wherein the inner mainadmission port 12 is directly connected to the exhaust pipe 31. Sincethe outer main admission port 13 is closed by the piston 3, fluid issupplied to the outer end 6 of the c linder 2 through the branch pipe18, the chec valve 37, the pipe 35 and the auxiliary port 33. The piston3 is now moved toward the inner end 11 of the cylinder 2, finallyclosing the inner main port 12 and dischargin the remaining fluidthrough the inner relie valve 38 when the kinetic energy of the piston 3and associated parts is translated into heat energy that is carried bythe discharging fluid to the storage chamber 22.

While I have shown only one form of embodiment of my invention, for thepurpose of describing the same and illustrating its principles ofconstruction and operation, it is apparent that various changes andmodifications may be made therein without departing from the spirit ofmy invention and I desire, therefore, that only such limitationsshall bemade thereon as are indicated in the a pended claims or as are demandedby t e prior art.

I claim:

1. A fluid motor having a pair of main ports, and a fluid-impelledmember having different effective pressure areas respectivelyoperatively related with said ports a pump having a discharge port and.a suction port, means for connecting said discharge port to that 'oneof said main ports related to the lesser of said effective pressureareas and the other main port to said suction port and thereafterconnecting said discharge port to both of said main ports, auxiliaryports ad jacent to said main ports, means including relief valves forconnecting said auxiliary ports to said suction port, and meansincluding check valves, whereby said auxiliary ports may be connected tosaid pump discharge port. 7

2. Apparatus comprising a cylinder provided with a piston havingdifferent efl'ective pressure areas at opposite sides, and main portsfor admitting actuating fluid to the opposite sides of said piston, anauxiliary port for each main port, a pump having discharge and suctionports,'a pipe system including independent branches connecting the mainports of the cylinder with the dis charge port of the pump, a bypassfrom each of said branches to the adjacent auxiliary port, a check valvein each of said bypasses, a three-way valve confined entirely to thatbranch which feeds the cylinder on the side of the piston of greatereffective area and adapted in alternative positions to connect theassociated main port with the discharge and suction ports of the pumprespectively, a bypass from each of said auxiliary ports to the suctionport of the pump, and a loaded valve in each of the last-named bypasses.

3. In a closed fluid system, the combination with a cylinder having mainports, and

' a fluid-actuated piston within said cylinder,

said ports being positioned to be closed by the piston as the latterapproaches the ends of its stroke respectively, of a pump, and meansproviding for actuation of the piston through the medium of fluidpressure from said pump applied to said main ports, an auxiliary portfor each of said main ports also connected with the discharge of saidpump for application of fluid pressure to the cylinder when therespective associated main ports are closed by said piston, a loadedrelief valve for each of the auxiliary ports, and means controlled bysaid valves for connecting the auxiliary ports with the pump suction.

EARL OANN ON.

